As borne witness by its door, the collegiate church was founded in the 12C by the bishop of Mondoñedo and finished by the archbishop of Santiago de Compostela, Diego Gelmírez. In the 18C, buttresses and the façade were added. Its inner columns are slanted due to the weight of the vault. All that remains of the cloisters, by Master Mateo or his school, is the wing that spans the church buttresses, whose elegant twin arches are adorned with floral and foliage motifs.